Pre- and postharvest strategies for control of Phacidiopycnis rot in D’anjou pears
C.L. Xiao and R.J. Boal.
Journal of Plant Pathology Volume 90 (2, Supplement) August 2008, Book of Abstract, 9th International Congress of Plant Pathology, August 24-29, 2008 Torino,Italy,. 507 pages.
2008
บทคัดย่อ
Pre- and postharvest strategies for control of Phacidiopycnis rot in D’anjou pears
Phacidiopycnisrot caused byPotebniamyces pyri(anamorphPhacidiopycnis pyri) is a common postharvest fruit rot disease ind’Anjou pears grown inWashington State,USA.P. pyriis associated with dead bark and twig dieback of pear trees in the orchards. Infection of pear fruit by the fungus occurs in the orchards, but symptoms develop in storage. In this study, selected pre- and postharvest fungicide programs were evaluated in 2005 and 2006 for control ofPhacidiopycnisrot. Fruit was inoculated in the orchard with a conidial suspension of the fungus at 3 weeks before harvest. Part of the fruit was sprayed with a premixed formulation of pyraclostrobin and boscalid (Pristine) or thiophanate-methyl at 7 days before harvest, and the remaining fruit was either not treated as controls or dipped in fludioxonil, pyrimethanil or thiabendazole solutions after harvest. Fruit was stored at 0°C for 7 months andPhacidiopycnisrot (stem-end and calyx-end rot) was monitored periodically. Pristine and thiophanate-methyl reducedPhacidiopycnisrot by 41-44% and 77-86%, respectively, in comparison with the nontreated control. Thiophanate-methyl was significantly more effective than Pristine. Fludioxonil, pyrimethanil and thiabendazole alone provided similar levels of control and reducedPhacidiopycnisrot by 88-100%. The results indicate that although infection of pear fruit byP. pyrioccurs before harvest, a preharvest fungicide applied within 7 days before harvest or a postharvest fungicide applied prior to storage can be effective for control ofPhacidiopycnisrot in d’Anjou pears.